Residents of the Cedar Grove Estate in Kiama believe a proposed 98-lot subdivision on the ridge to the south will create dangerous traffic conditions through the estate's narrow streets.
Kiama Municipal Council last week endorsed a planning proposal to rezone the nine-hectare site, between the Cedar Ridge and the Cedar Grove estates, from rural to low-density residential.
Access to the proposed estate will be up an embankment from Lilly Pilly Way in Cedar Grove.
The existing Cedar Grove Estate contains 63 residential lots and a 20-dwelling medium density development.
A traffic assessment indicates traffic volumes in Cedar Grove will jump from 770 vehicles a day to 1750 a day once the 98-lot development is complete.
A resident action group called LiPAC (Lilly Pilly Action Committee) has been formed to fight the proposed access.
Spokesman Mike Yalden said the group was not opposed to the subdivision but believed access to the proposed estate should be to the south of the site, via unformed "paper roads" known as Cuba Street and Bland Street.
The residents have taken issue with the council's comment the estate's roundabout on Jamberoo Road was not dangerous.
The council acquired RMS accident data that said there had been only one serious accident in the vicinity of the Cedar Grove Estate in the past five years, which involved a cyclist.
Mr Yalden said the RMS figures were based on serious injury only, and a survey of Cedar Grove residents found that two cars had been written off through accidents at the roundabout and another within the estate in the past 12 months alone.
He said the proposed access road was through a "forested buffer zone", established to provide a barrier between rural and residential land, which people buying into Cedar Grove were told would remain.
"Now the site is being rezoned they say they don't need the buffer any more," Mr Yalden said.
Kiama Mayor Brian Petschler said it was important for residents to remember that while the rezoning had been endorsed, the development would still be the subject of a separate development application process.
However, Cr Petschler believed the roundabout on Jamberoo Road was built to a standard that had the capacity for higher traffic volumes and a move to create an access road to the south would create further issues to the south, including the need to widen roads in the Cedar Ridge Estate and build a road outside the accepted boundary of the Kiama township.